Spain and beyond
Spain is a high-demand example, not the whole market.
Spanish telework and digital nomad visa instructions commonly point to contracts, company certificates or proof, apostilled foreign documents, and official translation where required. Other destinations can ask for similar proof with different wording, timing, and acceptance rules.
We also see document routes around Portugal, Italy, Greece, Croatia, Estonia, Malta, Mexico, Georgia, Japan, and other countries. The country name starts the route, but the receiving office and document source finish it.